This invention relates to wheelchairs, and more particularly, to hand-propelled wheel chairs.
Over the years a variety of wheelchairs have been developed to aid paraplegics and hospital patients. Typifying these wheelchairs and similar devices are those shown in U.S. Pat. Nos. 91,602, 882,248, 1,687,812, 2,576,413 and 3,107,105. These prior art wheelchairs have met with varying degrees of success.
Conventional hand-propelled wheelchairs that are in common use today, typically require a repetitive two-stroke action to permit the paraplegic or patient to manually drive the wheelchair. The repetitive two-stroke action consists of a power stroke, in which the user forcefully pushes the rims of the rear wheels forwardly to propel the wheelchair, and a return stroke or recovery stroke, in which the user reaches rearwardly and grabs the rims of the rear wheels. The power stroke requires a strenuous twisting action of the wrists which may result in injury. The return stroke produces no power in the wheelchair, even though the paraplegic or patient is working, which is inefficient and wasteful. Furthermore, during the return stroke, the wheelchair can lose momentum, abruptly change directions on uneven surfaces and roll backwards while climbing a ramp. This is very dangerous.
It is therefore desirable to provide an improved wheelchair which overcomes most, if not all, of the preceding disadvantages.